FIG. 7 is a block diagram illustrating a conventional example of a case where an expansion image processing board 106 (extended functionality interface, also referred to as EFI) is used in a network printer (multifunction printer) 102 having an image processing board 105 installed therein.
The network printer 102 illustrated in FIG. 7 includes an image forming section 122, an image input section 124, and the image processing board 105. The image processing board 105 includes a first printer function control section 108, a first scanner function control section 109, and a first interface section 110. The image processing board 105 is connected through the first interface section 110 to a LAN 125 where a computer 103 of a user exists. The first printer function control section 108 controls the image forming section 122. The first scanner function control section 109 controls the image input section 124.
To the first interface section 110, a10 is assigned as a private IP address on the LAN 25 (a private IP address of the image processing board 105). To the first printer function control section 108, a plurality of ports (port numbers P1 through Pn) respectively corresponding to printer functions are assigned. Similarly, to the first scanner function control section 109, a plurality of ports (port numbers Q1 through Qm) respectively corresponding to scanner functions are assigned.
Image data from the computer 103 of the user is fed to the first printer function control section 108 via the first interface section 110. The first printer function control section 108 outputs a control signal to the image forming section 122 in accordance with the image data. This allows an image to be formed (printed out). Further, scanned data from the image input section 124 is fed to the first scanner function control section 109. The first scanner function control section 109 outputs image data in accordance with the scanned data, and the image data is fed to the computer 103 of the user via the first interface section 110 and the LAN 125.
Now, in order to use the expansion image processing board 106 in the network printer 102, the image processing board 105 is replaced with the expansion image processing board 106 (The image processing board 105 is uninstalled from the network printer 102, and then the expansion image processing board 106 is installed in the network printer 102.).
As illustrated in FIG. 7, the expansion image processing board 106 includes a second printer function control section 118, a second scanner function control section 119, and a second interface section 120. The expansion image processing board 6 allows the network printer 102 to realize functionality greater than that of the image processing board 105.
When the expansion image processing board 106 has been installed in the network printer 102, an intra-device IP address a10 on the LAN 125 is newly assigned to the second interface section 120. Note that, since specified port numbers are generally used for particular functions and particular data exchanges, the second printer function control section 118 uses port numbers P1 through Pn (the same port numbers as those of the first printer function control section 108) respectively corresponding to the printer functions, and the second scanner function control section 119 uses port numbers Q1 through Qm (the same port numbers as those of the first scanner function control section 109) respectively corresponding to the scanner functions.
Given as publicly known documents involving a relevant technique are Japanese Laid-Open Patent Application No. 18639/1997 (Tokukaihei 9-18639; published on Jan. 17, 1997) and Japanese Laid-Open Patent Application No. 41268/2002 (Tokukai 2002-41268; published on Feb. 8, 2002).
However, in the above conventional example, in order to use the expansion image processing board 106, the previously used image processing board 105 must be replaced with the expansion image processing board 106.
Therefore, the image processing board 105 and the expansion image processing board 106 cannot be used in the following manner: the image processing board 105 and the expansion image processing board 106 are used concurrently (the user suitably selects from among the functions of them) so that part of functions of the image processing board 105 previously used by the user (e.g. common functions that are equal in performance between the image processing board 105 and the expansion image processing board 106) is used continuously.
Further, when the expansion image processing board 106 is installed, the LAN 125 must assign a new IP address to the expansion image processing board 106.